My prius user from Thailand. I found the service manual that show 12v battery is "lead-Acid Battery". but I heard that everyone recommend to replace them to be Optima Battery(AGM battery). What kind of original 12v battery from Toyota factory? Lead-Acid or AGM? Can I replace it to be Lead-Acid Battery? price is double or triple between AGM with SMF. Please advise.
AGM is still a lead-acid battery, but better for most applications. Given it's size and duties, I'd expect it to be an AGM battery. I think all Toyotas come with AGM batteries now, but I'd need to confirm that.
"AGM" means "absorptive glass mat". The electrolyte (sulfuric acid) is held by a glass fibre mat. "Just in case" your car is turned upside down, or on its side. The acid will be held in the mat. The vent is there to prevent any vapours coming out of the battery from entering the cabin. All because the battery is IN the cabin. Yes, it's quite a bit more expensive. No, it doesn't seem to last any longer. But I'm just bitter after having to replace mine after only 3 1/2 years. The GIV 12V battery is under the hood. That's a $100 savings every 3-5 years when it has to be replaced (because a less expensive non-AGM battery could be used - but I suspect it's still the expensive type even though I haven't seen one yet). See, I'm really bitter.
